Mothers and pups sometimes get confused on the beach. It happened Monday, when three mothers contended over four pups. None of the visitors witnessed the births, so we observers were as confused as the seals.
My guess was that the missing mother was about ten feet away. A female was sleeping just beyond the group. The large reddish spot on the sand suggested that a birth had recently happened there, and she was the likely mother.
Two of the mothers barked and threatened each other. The third quietly tended to two pups. The bright sunshine causes sharp shadows that make this photo difficult to decipher. Here one of the mothers barks at a pup, while her rival tosses sand on her back.
All four of the pups were very new, and I didn't see any of them nursing. The two pups affiliating with the quiet mother were sociable toward each other, nosing each other companionably.
The beach isn't terribly crowded yet, but this group managed to get their signals crossed. I don't know whether anyone has every documented switched pups. It seems like something that could happen, without ill effects. So long as a pup gets care and adequate milk, it wouldn't be important that it be from its biological mother. Last year lots of mothers nursed other pups after theirs died in winter storms.
We'll see how the season progresses. Few females have chosen to settle on the north end of the rookery, where the beach has eroded.